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#268803 - 04/11/2005 10:55 No power up on AC
Pac
new poster

Registered: 04/11/2005
Posts: 8
Hi Guys,
My MkII won't boot up on mains any more,have check the PSU and it all looks good 15v at 1 amp.

No problems with the sled in the car boots fine.
Any thoughts, ideas welcome.

Thanks Pete

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#268804 - 04/11/2005 14:01 Re: No power up on AC [Re: Pac]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
Have you opened up the unit to see if at least the red LED near the front comes on with AC? If not, measure the voltage at the large header with no jumper on it near the power jack in the back. You should see your AC supply voltage there. If you don't, work back to power jack and see if it is working. If you are getting supply voltage, then you need to measure the voltages at the 3 and 5 volt headers (they are the ones in the right back side of the unit). If you don't see these voltages but do see your AC supply voltage, chances are the MAX1631 is not operating for some reason.

We once had this very problem and it turned out to be some loose resistors.

Post what you can find and we can diagnose the problem further.

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

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#268805 - 04/11/2005 17:45 Re: No power up on AC [Re: Pac]
tfabris
carpal tunnel

Registered: 20/12/1999
Posts: 31594
Loc: Seattle, WA
Quote:
have check the PSU and it all looks good 15v at 1 amp

Quick sanity check...

When you say "check the PSU", do you mean you actually put a 1 amp load on it and measured the voltage?

Or by "check the PSU", do you mean you read the specs on the label?

Because the first thing I would suspect is a bad PSU.
_________________________
Tony Fabris

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#268806 - 04/11/2005 18:07 Re: No power up on AC [Re: maczrool]
Pac
new poster

Registered: 04/11/2005
Posts: 8
Cheers Stu will give that a go on Sunday my first day off
and post my findings.

Regards Pete

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#268807 - 04/11/2005 18:24 Re: No power up on AC [Re: tfabris]
Pac
new poster

Registered: 04/11/2005
Posts: 8
Hi Tony,

I put a meter across the psu just to check a voltage was present hoping it was a duff psu it check out ago with regard the voltage..to be fair i just turned the avo over to amps and it read 1amp...is that not what the RIO needs to run with regard to amps ?



don't bother with the sanity check we're all quite mad don't you know!

Cheers Pete

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#268808 - 04/11/2005 18:30 Re: No power up on AC [Re: Pac]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
Quote:
to be fair i just turned the avo over to amps and it read 1amp...

Uh. That's not how you measure current. You put the multimeter inline with something to measure the amount of current it is using. If you just connect it across the PSU then you're effectively shorting it out which can be dangerous. Just look at the label to work out the maximum amount of current the PSU can supply. Use a multimeter to work out the voltage. In this case, your PSU is probably a 12V unregulated one and should be okay powering the empeg.

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#268809 - 04/11/2005 18:44 Re: No power up on AC [Re: Pac]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Bad power socket? The solder around the contacts cracks.
_________________________
One of the few remaining Mk1 owners... #00015

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#268810 - 04/11/2005 20:08 Re: No power up on AC [Re: schofiel]
Pac
new poster

Registered: 04/11/2005
Posts: 8
Trev
It has to be said I can be a bit of a cowboy..I blame my Dad
he was an electronics tech for southern electric while I'm sure his work was safe. our house needed a little to be desired.he tried to get me into all but due to cronic colour blindness it was a no go.

But as per schofiel post I'll check for dry joints..

Thanks for the advice guys lots to be getting on with.
I might enlist the help of a friend who is a PC techie his colour vision is spot on

Pete

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#268811 - 06/11/2005 14:21 Re: No power up on AC [Re: maczrool]
Pac
new poster

Registered: 04/11/2005
Posts: 8
Hi Stu,
Followed your walk thru and have volts at header near power insert but nothing at 3 and 5 volts header.
I guess its the MAX1631 then..looks like a tricky little bugger to get out.

Regards Pete

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#268812 - 06/11/2005 21:36 Re: No power up on AC [Re: Pac]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
It may be the MAX1631 or it could be something controlling it that is not functioning properly. Get a copy of the MAX1631 datasheet for the pinouts. I can't remember which pins they are, but check at the pins where the 3 and 5 volts outputs are on the chip to eliminate broken traces to the headers as the culprit. Also make sure the chip is receiving supply voltage at the input pins. There are a few shutdown pins on there too and if they aren't as the datasheet specifies, then the chip won't give you output. If the unit works in the car as I believe you said it was then the chip should be ok as it supplies the whole digital side of the board.

See if you can narrow things down a bit. Just be careful when measuring not to short out adjacent pins.

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

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#268813 - 07/11/2005 16:34 Re: No power up on AC [Re: Pac]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
I vastly doubt the the MAX has blown. It's almost bulletproof. Something has failed that is preventing it from turning on, either a line voltage enable or an output short.
_________________________
One of the few remaining Mk1 owners... #00015

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#268814 - 09/11/2005 18:24 Re: No power up on AC [Re: maczrool]
Pac
new poster

Registered: 04/11/2005
Posts: 8
Hi Stu,
The MAX1631 checked out ok,Couple of stupid questions
Is it poss to get hold of another motherboard?
Or could I use one of Mark Lords sleds.
I only ask as we are getting a bit ..Well a lot beyond my technical abilities.

Cheers Pete

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#268815 - 09/11/2005 19:00 Re: No power up on AC [Re: Pac]
maczrool
pooh-bah

Registered: 13/01/2002
Posts: 1649
Loc: Louisiana, USA
What do you mean the MAX checked out ok? While on AC power, all the enable pins have proper voltage going to them (I think its 5 volts) and more importantly, do all the 3.3 and 5 volt outputs have 3.3 and 5 volts on them?

Mark Lord's docks should work if the car sled works.

Motherboards are at least from what I've heard, hard to come by. They usually come with the rest of the unit attached.

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

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#268816 - 09/11/2005 19:49 Re: No power up on AC [Re: maczrool]
Pac
new poster

Registered: 04/11/2005
Posts: 8
Stu,
To be fair I did'nt get to involved with it as a mate of mine who is more up to speed with that sort of thing, checked it out for me.
Having said that he did comment on one pin not being 3.5 volts as he would have expected to see on the power in side I think it read about 2.8 volts if memory serves it was the top right hand pin looking at the unit from the front.
I would confirm that but his mobile is off at the mo

Pete

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