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#198566 - 15/01/2004 05:01 Empeg stuck in AC mode. Dead Transistor is the culprit.
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
I recently had a short in my cigarette lighter and now the Empeg is stuck in AC mode. With the help of my backup unit, I was able to trace the problem to a transistor. It is located below the upper right hand corner screw on the main board. It has a marking "MG A6" on it. Does any one know where I can get a replacement for this part or maybe a similar one? Any info is appreciated. Thanks.

- Tom

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#198567 - 15/01/2004 07:20 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: TRUNGLE]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
Sure it's a transistor? I'm guessing since I can't see inside my empeg right now. Is it a SOT23 package? It could be single or a dual diode which can quite easily look like a transistor

See here:
http://www.semiconductors.philips.com/pip/BAS16W.html
http://www.repairfaq.org/REPAIR/F_SMD_trans.html
_________________________
Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#198568 - 15/01/2004 07:31 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: TRUNGLE]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Ah...maybe that's the same problem I have... I'm pretty sure mine is not the AC sensor switch. I had a similar short when installing in my wife's car and one time when I put the empeg in it went pop and turned off. Since then, it will only boot in AC mode. PLEASE let me know if that fixes the problem.
_________________________
~ John

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#198569 - 15/01/2004 11:52 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: TRUNGLE]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31563
Loc: Seattle, WA
If replacement of this transistor solves the problem, please notify me or follow up on this thread. I should like to update the FAQ entry about the AC sensor switch if that's the case.
_________________________
Tony Fabris

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#198570 - 16/01/2004 01:32 Re: Empeg stuck in AC mode. Dead Transistor is th [Re: TRUNGLE]
alex25
member

Registered: 30/06/1999
Posts: 179
Loc: Switzerland

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#198571 - 16/01/2004 05:48 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: Shonky]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
Thanks for the info. You're right, it's a diode in a SOT23 package. Looks like a common component. I'm going to see if I can find one in my pile of surplus parts.

http://www.fairchildsemi.com/ds/BA/BAS16.pdf

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#198572 - 16/01/2004 06:45 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
Fixed! My player is now switching between AC/DC mode. I found an "A6" diode on a Diamond Multimedia Supra Express 56i ISA modem. I'm glad I didn't chuck it when I switched to an all PCI MB. I'm attaching a picture of the component for those that would like to see what it looks like.

I hope this info will help you fix your player.

In DC mode, I was measuring 2.53V on pin 1 of the diode when it should be 0.5V


Attachments
197342-A6-640x480.JPG (255 downloads)


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#198573 - 16/01/2004 06:50 Re: Empeg stuck in AC mode. Dead Transistor is th [Re: alex25]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
So does this mean that if the player is stuck in DC mode then it is the buffer ic and if it stuck in AC mode then is the diode? Oh well, I'm just glad that your player and my player is working like it should.

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#198574 - 16/01/2004 06:53 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: tfabris]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
During the course of this little venture, I also decided to upgrade the HD to a Seagate Momentus 40GB. Couldn't have done it without the guidance of your excellent FAQ. Thanks Tony.

Can you edit the thread title to Defective Diode instead of Dead Transistor?

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#198575 - 16/01/2004 07:51 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: TRUNGLE]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Could you elaborate (and use small words for the EE ignorant) on how to test to see if this is the same issue on my player? I have my player dissected and a VOM handy.

EDIT: Your picture was too large...it didn't attach
_________________________
~ John

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#198576 - 16/01/2004 10:39 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
I think I've found it...is it between the +3v jumper and the top of the board? Also, how do I test it? Do I just put the red on pin one and the black on the player case and measure the voltage?

I have an Mk2...so I imagine it could be in a slightly different spot on my board.
_________________________
~ John

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#198577 - 16/01/2004 17:39 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
Low Res: http://www.trung.com/empeg/A6-640x480.JPG
High Res: http://www.trung.com/empeg/A6-1280x960.JPG
Pin 1 and 3: http://www.trung.com/empeg/A6-PIN1AND3.JPG

How to test the diode:

1) See the pictures to help you locate the component.

2) You need to power your empep like if it was in the car before running the test. Don't plug the AC adapter into the power jack. Power the unit through the sled connector and make sure that the 3A fuse on the Yellow line is good. I use a regulated 13.8V power supply but you can use the AC adaptor. If you want to use the AC adaptor then the center is Positive and the outside part is Ground. Connect the Yellow line to the Positive center and the Black wire to the Ground of the AC adaptor. Since you are dealing with power lines please take your time and verify all the connections before applying power.

3) Connect the black lead of the VOM to the chassis of the player.

4) Now find the floppy power connector. It has a Blue, Orange, Black, and Red wire on it. Use the red lead of the VOM to check for power on the Red line. Double check your connections if you are not getting power.

4) Use the red lead of the VOM to measure the voltage at point 1. (see picture) The work area is very tight, so be careful you don't create a short.

5) If the diode is working, then the reading on the VOM should be about 0.5V. My defective diode was reading 2.53V.

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#198578 - 20/01/2004 15:49 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: TRUNGLE]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Thanks for the great info!

I've been putting off posting back until I can get some pictures.
Unfortunately, my MK2 board does not have that diode (at least in the same place.) Evidently the rearranged some of that stuff between the MK2 and the MK2a.

The only pic I could find that looks like mine is this lower-res image I cribbed from mrmunsell's fuse replacement guide.



I'm going to snap some higher res pics soon and hopefully figure out what could possibly be the issue.

Ideally, if PCA could comment on what would be the likely suspect...

Stay tuned...
_________________________
~ John

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#198579 - 22/01/2004 11:35 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
I've got my empeg on the test bench, but am not having any luck figuring out what's wrong. (Mostly from lack of knowing what to check.)


The camera I borrowed doesnt seem to be much better than the one above...here's the best shot I could get, even in macro mode.



I'm afraid I'll have to send it off to someone who knows what they are doing.
_________________________
~ John

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#198580 - 26/01/2004 03:48 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
The component in there is only present in the mk2a, and helps to protect a 74LVX04 (IC33); on a mk2, pin 9 of one of these (the one nearest the unused internal LCD connector) connected directly to the power jack switch.

If AC/DC sense dies on a MK2, and the fault is *not* with the plug itself, then you need to swap out IC33 which is a bit harder than a SOT23 but not too bad. The biggest issue is getting a TSSOP 74LVX04, in fact.

Hugo

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#198581 - 28/01/2004 13:22 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: altman]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
[blank stare] Oh. [/blank stare]

/me shuffles off to the back of the support line.
_________________________
~ John

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#198582 - 28/01/2004 13:29 Re: Empeg stuck in AC mode. Dead Transistor is th [Re: altman]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
Seems easy enough to get a TSSOP 74LVX04. Quite easy to find and purchase actually. So the diode protects IC33 in a MK2A? And if the diode goes out, apparently the layout is such that IC33 still survives. Replacing TSSOP and SOT is a piece of cake.

Stu
_________________________
If you want it to break, buy Sony!

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#198583 - 28/01/2004 13:33 Re: Empeg stuck in AC mode. Dead Transistor is th [Re: maczrool]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
You've got mail via your website.
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~ John

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#198584 - 28/01/2004 16:59 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: altman]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
Which one is IC33? This is a picture of a RIO/MK2a board.

The IC is available at Mouser Electronics
http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=304482&e_categoryid=97&e_pcodeid=51218



Attachments
199562-IC33.JPG (226 downloads)


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#198585 - 29/01/2004 06:05 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: TRUNGLE]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
The top left one, ie the one closest to the connector labelled LCD

Hugo

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#198586 - 29/01/2004 13:47 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: altman]
TRUNGLE
new poster

Registered: 15/01/2004
Posts: 11
I thought that was the one you were talking about but was not quite sure. Thanks for the info.

Tom


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#198587 - 26/08/2005 01:22 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: altman]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
Which one is IC33 in an MK2? There are buffer chips on either side of the LCD connector pads.

Stu
_________________________
If you want it to break, buy Sony!

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#198588 - 15/09/2006 12:28 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: maczrool]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Seeing as much of the brain trust is in one location this weekend, I thought I'd bring this thread back from the long dead.

What else can affect the ability to dectect AC or DC power? I had Ian replace the LVX04 chip at the empeg meet in Cincy two years ago. That didn't fix the problem, so Mark replaced the power jack for me a couple weeks ago. Still no dice. Empeg seems to work quite well other than this.
_________________________
~ John

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#198589 - 15/09/2006 15:42 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
Pretty much you have only the level shifter IC (LVX04) and the GPIO on the Strongarm on an MK2 and the MK2A has a diode. I think maybe there is a voltage divider resistor network with two 12K resistors as well.

Nothing else there.
Stu
_________________________
If you want it to break, buy Sony!

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#198590 - 16/09/2006 05:43 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31563
Loc: Seattle, WA
Quote:
What else can affect the ability to dectect AC or DC power?

Damage to circuit traces or solder joints somewhere on the PCB?

Fried code in the power-control PIC?

Disclaimer: These are wild guesses from someone who knows nothing of the hardware.
_________________________
Tony Fabris

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#198591 - 04/12/2006 15:51 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: JBjorgen]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
Quote:
What else can affect the ability to dectect AC or DC power? I had Ian replace the LVX04 chip at the empeg meet in Cincy two years ago. That didn't fix the problem, so Mark replaced the power jack for me a couple weeks ago. Still no dice. Empeg seems to work quite well other than this.


Did you ever get this sorted out?

We've got an MK2 unit which we replaced both those parts in also and it did not fix the problem either. In addition to not sensing AC properly, this one also has trouble starting up on occasion. The display light will turn on and flash a couple times, but the player doesn't boot and the display remains blank except for the heating wires. The only solution is to pull the power and reapply.

The problem doesn't seem to be any of the resistors in the path. Does anyone know if these problems could be caused by the power control PIC?

Stu
_________________________
If you want it to break, buy Sony!

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#198592 - 04/12/2006 17:13 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: maczrool]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3582
Loc: Columbus, OH
Nope. Never did solve it. If I have Hijack Force DC mode, everything seems to work as it should, so I never bothered. I'd be very interested if you find a solution. Hugo? Patrick? Anyone out there?
_________________________
~ John

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#198593 - 05/12/2006 01:42 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: maczrool]
altman
carpal tunnel

Registered: 19/05/1999
Posts: 3457
Loc: Palo Alto, CA
Hmmm. Usually when the display light goes out and nothing happens it's the 60v PSU trying to start but taking too much current and causing the system to brownout (and cycle). Did you have a look at the 60v supply? This should come on the instant the standby light stops flashing.

Don't think it'd be the power PIC (it's the PIC that turns the display on).

Hugo

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#198594 - 05/12/2006 12:49 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: altman]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
Quote:
Hmmm. Usually when the display light goes out and nothing happens it's the 60v PSU trying to start but taking too much current and causing the system to brownout (and cycle). Did you have a look at the 60v supply? This should come on the instant the standby light stops flashing.

Don't think it'd be the power PIC (it's the PIC that turns the display on).

Hugo


It's not the display, we get 58+ volts. The hard drives even spin up and stay spinning. I am trying running with only one HD at a time and see if this could be the issue. I'll report back if this fixes the non-booting issue.

Any ideas about why a number of units can't detect AC/DC properly even after replacing the buffer and power jack?

Thanks,
Stu
_________________________
If you want it to break, buy Sony!

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#198595 - 05/12/2006 13:28 Re: Empeg stuck in AC mode. Dead Transistor is the culprit. [Re: maczrool]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14472
Loc: Canada
Quote:
this one also has trouble starting up on occasion. The display light will turn on and flash a couple times, but the player doesn't boot and the display remains blank except for the heating wires. The only solution is to pull the power and reapply.


This often happens on perfectly good units when rebooting via the Hijack menu. But it should not happen on any fresh power-up.

-ml

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