A3010 CMOS issue after battery replacement

[mattdy4]

Afternoon all

I replaced the original CMOS battery on an A3010 I aquired recently with two Eneloop's in an AA battery holder. I'm getting 2.6v when measured from the batteries / terminals but when power is off for more than five minutes then it boots to a black / dark grey screen with no POST just a faint beep. Clear CMOS and it POST's and boots to desktop without issue but obviously all settings are lost.

As the original battery was fairly well depleted (<1v) and I've got no history of the machine I don't know if the CMOS had an issue previously as always had to Del-Power on. Any ideas where to check first?

Should add that the battery had practically zero leakage and the board appears clean enough though still did the standard clean up job on the area first

[DutchAcorn]

What voltage do you measure over pins 4 and 8 of the cmos chip when power is off?

[flaxcottage]

I've had problems with Eneloop batteries. They show very high self-discharge at times. I'd check them first.

If the CMOS still fails to hold its settings are the correct voltages being applied to the chip when the A3010 is off.

I've also noticed that Axxxx machines need to be powered on for at least 30 minutes first time before they will boot correctly. Maybe leave the machine on for a time before switching off.

[mattdy4]

IC5 is not measuring anything...

[mattdy4]

I've had problems with Eneloop batteries. They show very high self-discharge at times. I'd check them first.

If the CMOS still fails to hold its settings are the correct voltages being applied to the chip when the A3010 is off.

I've also noticed that Axxxx machines need to be powered on for at least 30 minutes first time before they will boot correctly. Maybe leave the machine on for a time before switching off.

I'll try leaving it on for a while. The batteries are showing 1.3v each and 2.66v in series

[mattdy4]

I've had problems with Eneloop batteries. They show very high self-discharge at times. I'd check them first.

If the CMOS still fails to hold its settings are the correct voltages being applied to the chip when the A3010 is off.

I've also noticed that Axxxx machines need to be powered on for at least 30 minutes first time before they will boot correctly. Maybe leave the machine on for a time before switching off.

I'll try leaving it on for a while. The batteries are showing 1.3v each and 2.66v in series

Left it on for an hour before leaving it switched off for 7-8 minutes. Turning back on it posts but get blinking underscore prompt or Supervisor prompt. Typing *desktop gives errors

[IanS]

IC5 is not measuring anything...

If the RTC chip has no power, it won't remember anything.
Check the connections to R73, R61 and R60..

[mattdy4]

Thanks Ian and everyone else, found this out which was pretty definitive - viewtopic.php?f=16&t=12245&p=155838&hilit=r73#p155838

I guess that the battery had leaked more than I thought! R60 - R61 link looks fine though at least so hopefully just that. Pads look pretty corroded and not entirely sure if this is in my skill set to replace so will probably have to find a man that can

[DutchAcorn]

I guess that the battery had leaked more than I thought! R60 - R61 link looks fine though at least so hopefully just that. Pads look pretty corroded and not entirely sure if this is in my skill set to replace so will probably have to find a man that can

From the picture it seems that R60 is no longer there...

[mattdy4]

Lookign at the service manual R60 on a A3010 is listed as RES 180R SMD 5%0W100805

Would this be a suitable replacement?

https://www.ebay.co.uk/itm/180ohm-180R0 ... 1807245106

[danielj]

Yup (Make sure everything's clean/neutralised first, plus you may well have to use hookup wire to connect things up if the traces/pads have died)

d.

[1024MAK]

If the copper PCB pads for R60 no longer exist, you may find it easier to use a normal 0.25W (250mW) or 1/4W wire ended resistor. Carbon film or metal film, any tolerance equal to 5% or better (2% or 1%) will work okay.

Mark