Sounds like an excuse to buy a new toy
Search found 59 matches
- Fri May 17, 2024 9:59 pm
- Forum: Hardware
- Topic: Spectrum +2 grey dead short
- Replies: 10
- Views: 348
- Fri May 17, 2024 9:32 pm
- Forum: Hardware
- Topic: Spectrum +2 grey dead short
- Replies: 10
- Views: 348
- Fri May 17, 2024 8:45 pm
- Forum: Hardware
- Topic: Spectrum +2 grey dead short
- Replies: 10
- Views: 348
Re: Spectrum +2 grey dead short
Followed the voltage gradient drop and, nearly, voltage level improved but not completely. C68 is an odd looking inductor
- Fri May 17, 2024 6:09 pm
- Forum: Hardware
- Topic: Spectrum +2 grey dead short
- Replies: 10
- Views: 348
Re: Spectrum +2 grey dead short
4 digit, 4000 counts auto range. I think
mV
- Fri May 17, 2024 1:07 pm
- Forum: Hardware
- Topic: Spectrum +2 grey dead short
- Replies: 10
- Views: 348
- Fri May 17, 2024 11:45 am
- Forum: Hardware
- Topic: Spectrum +2 grey dead short
- Replies: 10
- Views: 348
Spectrum +2 grey dead short
Hi, I liked my friend's Spectrum +2 so much I decided to get my own but this one is not in a good shape. There is a dead short across the power rails. I have set the bench power supply limit at 600ma for now. Nothing appears to be getting hot. PCB looks OK, bit dirty, and no obvious signs of any pre...
- Sun May 12, 2024 3:12 pm
- Forum: Hardware
- Topic: FIXED Spectrum +2 grey RAM fault but RAM is good
- Replies: 31
- Views: 798
- Sun May 12, 2024 12:49 pm
- Forum: Hardware
- Topic: FIXED Spectrum +2 grey RAM fault but RAM is good
- Replies: 31
- Views: 798
Re: Spectrum +2 grey RAM fault but RAM is good
Bit of progress. :D 20240512_114244_exported_6245.jpg The clue was a stuck key on bit 1 but also bit 4. Both of these bits from part of the joystick interface. So I removed the joystick controller IC and all RAM tests now pass and no stuck keys. Not booting yet but guess that is because I need a joy...
- Sat May 11, 2024 6:22 pm
- Forum: Hardware
- Topic: FIXED Spectrum +2 grey RAM fault but RAM is good
- Replies: 31
- Views: 798
Re: Spectrum +2 grey RAM fault but RAM is good
In summary. ZX Spectrum +2 (grey) displays typical RAM failure pattern on power on. Diagnostics ROM indicates IC31 bit 1 faulty. Removed IC31 and tested off board, and passed. RAM is good. Socketed IC31 and replaced with a new 4164 but faster speed. Problem still persists. Other actions taken but st...
- Sat May 11, 2024 6:04 pm
- Forum: Hardware
- Topic: FIXED Spectrum +2 grey RAM fault but RAM is good
- Replies: 31
- Views: 798
Re: Spectrum +2 grey RAM fault but RAM is good
If the fault is or has been intermittent, poor IC socket contacts, dry jointed solder joints, and PCB track faults are still possibilities. Mark Indeed, that is what I am afraid of. But the board is clean and in good visual condition and no previous work has been completed. As a precaution I reflow...