alexh wrote: ↑Mon May 23, 2022 9:12 am
Mine didn't look too bad when I first opened the case but when I started to clean it, tip-toe gently, simply applying the white vinegar (I just poured a little bit out of the bottle) washed away C154, C159 and R430 and their pads
Yeah, C153 had already gone when I got it, the rest seem to be well attached still, though connecting traces to a lot of resistors and caps nearby are bad. C153 is gone along with a trace, but I may have a spare 15pF SMD cap to hand, so I'll just have to concentrate on repairs.
A little worried that the RTC clock may be bad, so going to look see how available they are.
BTW I just booted with the FDD connected and it gave what looked like an error code flashed through the drive LED, so need to look at that too, though I am aware no RTC could also be the reason for that.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
atari030 wrote: ↑Mon May 23, 2022 11:50 am
It must be a machines that start with A problem. Had the same with my A2000 and A4000.
I love seeing a good restore after that kind of shenanigans.
I'll do my best to do a good restore
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
alexh wrote: ↑Mon May 23, 2022 12:44 pm
If it is broken too bad perhaps you might be able to use a podule RTC. They are £30 + pnp from CJE or 4D or perhaps make your own.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
So, the fact I'm getting POST codes from the FDD LED is a definite bonus, it means something is happening.
This is what I get by means of flashes from the FDD LED:
4 short
4 short
4 short
3 short 1 long
4 short
4 short
short long short long
1 long 3 short
Going by the info at retro-kit this is the problem:
Screenshot 2022-05-23 at 14.31.42.png (351.39 KiB) Viewed 1345 times
Which makes sense since the RTC/CMOS chip is currently removed. That seemingly is the only error. I have ordered a replacement PCF8583 just in case.
No display at present, but the POST codes are encouraging, though I still need to check the clocks as suggested over at Stardot.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
rubber_jonnie wrote: ↑Mon May 23, 2022 2:05 pm
But does that effectively replace the RTC (And I think to an extent settings) IC58? Or is it just a clock?
Yes I believe so, it replaces IC58. It is the CMOS RAM + Battery + RTC. It connects to the I2C bus on the podule connector. Ask over at StarDot if in doubt.
Have you tried the "Power-on-delete" or "Power-on-R" sequence to try to get it to the Supervisor prompt on VGA out?
(Hold delete or r keys when powering on)
While Ian said you can't boot to RiscOS without the CMOS RAM working maybe you can't boot to supervisor prompt?
I've had no hands on time with my A5000 only a bit of reading.
rubber_jonnie wrote: ↑Mon May 23, 2022 2:05 pm
But does that effectively replace the RTC (And I think to an extent settings) IC58? Or is it just a clock?
Yes I believe so, it replaces IC58. It is the CMOS RAM + Battery + RTC. It connects to the I2C bus on the podule connector. Ask over at StarDot if in doubt.
Have you tried the "Power-on-delete" or "Power-on-R" sequence to try to get it to the Supervisor prompt on VGA out?
(Hold delete or r keys when powering on)
While Ian said you can't boot to RiscOS without the CMOS RAM working maybe you can't boot to supervisor prompt?
I've had no hands on time with my A5000 only a bit of reading.
OK, so power on DEL needs the RTC/CMOS chip in place to work according to Ian over on Stardot.
I'll try power on plus r later.
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
Collector of many retro things!
800XL and 65XE both with Ultimate1MB,VBXL/XE & PokeyMax, SIDE3, SDrive Max, 2x 1010 cassette, 2x 1050 one with Happy mod, 3x 2600 Jr, 7800 and Lynx II
Approx 20 STs, including a 520 STM, 520 STFMs, 3x Mega ST, MSTE & 2x 32 Mhz boosted STEs
Plus the rest, totalling around 50 machines including a QL, 3x BBC Model B, Electron, Spectrums, ZX81 etc...
rubber_jonnie wrote: ↑Mon May 23, 2022 3:53 pm
OK, so power on DEL needs the RTC/CMOS chip in place to work according to Ian over on Stardot.
I'll try power on plus r later.
My A3000 was just blinky LED errors until a replacement CMOS chip was back onboard. No key combo would persuade it to show a screen.
Interestingly the chip was working until I started cleaning up the corrosion and then it stopped! They seem a bit flakey in general.
BW
DFB1 Open source 50MHz 030 and TT-RAM accelerator for the Falcon DSTB1 Open source 16Mhz 68k and AltRAM accelerator for the ST Smalliermouse ST-optimised USB mouse adapter based on SmallyMouse2 FrontBench The Frontier: Elite 2 intro as a benchmark