Centris 660AV doesn't boot from HD

[Forrest]

I decided to startup my 660AV that been sitting unused for about 9 years. No video. I checked the PRAM battery and found it was reading 1.4V, so I installed a new 3.6V 1/2 AA Lithium and the computer booted up and ran for about 2 hours off the original 230MB drive. For some reason, the 730MB (internal) was not showing. I turned the computer off and tried some SCSI terminators, without luck. The computer now only boots to the disk ?. Looking for advice - should I recap the motherboard, or install another power supply? I see a few power supply's on ebay for $35 - Astec (original is Astec), TDK and others.

 

[Byrd]

Hi Forrest,

going off your post you've tried two hard drives - a 230MB and 730MB?  If everything else is good, sounds like just the HD is hosed/subject to possible "stiction".  A new SCSI HD or SCSI2SD might be a good replacement.

JB

 

[Forrest]

I'm pretty sure the original internal 230MB drive works. I ran about 8 programs off it the other day - no problem. I'm thinking this is a power problem - not enough to run both internal hard drives at the same time. Could be a capacitor problem also. This machine was treated well - I bought it new in 1993.

 

[Byrd]

Treat the simplest fault first - suspect the HDs first (OS reinstall, reformat your internal 230MB drive), before looking at caps, PSU replacement.  If the HDs check out fine, use a multimeter to check PSU voltages.  After 9 years of no use, it's not unheard of for a HD to just decide to die suddenly.

 

[Macdrone]

I have had to recap 3 660's all with leaky caps.  They seem to share the same time frame as the 840av which all need recap also.  Lucking for the 660 the board is flat and the goo stays directly under the caps usually.

 

[Forrest]

Macdrone,

Thanks for the feedback. I checked the voltages on both hard drive power connectors and they are correct at +5V, +12V. So it seems this computer needs to be recapped. I didn't see the specs on the caps required for the 660AV on the 68kMLA Wiki. Could you post this info, so I can order the Tantalum caps?

 

[Forrest]

I ordered tantalum capacitors today to replace the leaking electrolytic's. The 660AV required (11) 47 uF, 16V, size 2412 (inches) and (2) 10 uF, 16V, size 1206 (inches).

The fan on the power supply was also making lots of noise, so I ordered a 80 x 80 x 20 mm, axial, ball bearing fan, 12V DC