So how bad is this C128?

[Boschloo]

This is a C128 I was sent a private offer to buy. Price is good. But, it's showing these issues on diagnostics screen and I'm new to the Commodore, so, I thought I'd ask here if this is one to avoid. Thanks.

[+OLD CS1]

Not knowing what these tests mean in context, I would definitely have concerns.  The cassette port being bad could be related to the CPU, but with the controler, serial, and user port failures, that tells me it has 6526 CIA failures.  Oh, and I just saw the chip diagnostics: bad CIAs and SID?  No way, unless you can get it cheap.

 

I would not pay more than $25 or $50 for this (I am also a hard-ass on price.)  CIAs may be difficult to find, and while you can get a modernized SID replacement, the cost of a proper replacement is going to run anywhere from $40 to $100.  A proper replacement will be required for games which use the random number generator, or if you want to use a mouse with GEOS.  I am still not sold on the FPGA replacements (spoken about in another thread.)

[+evg2000]

aren’t several of the things showing bad because there probably isn’t a test harness hooked  up? i think all of the first 5 in the right column are due to no test harness. 

[+OLD CS1]

2 minutes ago, evg2000 said:

aren’t several of the things showing bad because there probably isn’t a test harness hooked  up? i think all of the first 5 in the right column are due to no test harness. 

True enough.  You cannot trust those test results if there is no testing dongles or harness.  So, at this point, I would consider the unit untested.

[Boschloo]

47 minutes ago, evg2000 said:

aren’t several of the things showing bad because there probably isn’t a test harness hooked  up? i think all of the first 5 in the right column are due to no test harness. 

I don't know what a test harness is, but it's interesting that you mentioned it, because the seller himself said something about not having one. He said "Tested using just the diagnostic cartridge, which is why some tests came up bad. I do not have the full harness for the commodore 128, so I am unable to fully test that part of it."

[hofster]

As others said already, you need a harness for that diagnostic cartridge. I know that the first four failures and the keyboard open are expected without the harness. I'm not sure about the Interrupt failure.

 

Do you know the seller and do you trust them?

Have they been using this C128 without noticing any issues?

[Boschloo]

17 hours ago, hofster said:

As others said already, you need a harness for that diagnostic cartridge. I know that the first four failures and the keyboard open are expected without the harness. I'm not sure about the Interrupt failure.

 

Do you know the seller and do you trust them?

Have they been using this C128 without noticing any issues?

I don't know him, but, I ended up going with a different C128. I found one at an okay price, without any yellowing. It was untested but looked well kept. If it isn't great, at least the seller accepts returns. 

I also accidentally purchased the wrong monitor for it. Commodore 128 designer Bil Herd said the 1902 was the monitor created for the 128. I ordered what I thought was a 1902, but it turned out to be a 1902A. Hopefully I will overcome this mistake. The case design is entirely different. The 1902 had rear feet that allowed the front of the monitor to sit on the flat part of the C128. The 1902A doesn't have that feature. 

[+OLD CS1]

2 hours ago, Boschloo said:

it turned out to be a 1902A

https://www.lemon64.com/forum/viewtopic.php?t=54606

[eightbit]

I am fairly certain that the test you show is normal without a test harness attached. The test harness connects to both joystick ports, cassette port and user port for a proper test.

 

Without it the CIA's and SID will show bad as it is trying to test the ports and the CIA's control I/O processes and the SID plays a part because aside from sound it also controls potentiometer reading.

 

There's definitely not a harness attached in that picture so it makes sense. If you can get it for a reasonable price grab it even if you went with another one. The keyboards on these are impossible to find when you need a replacement...aside from buying a whole C128 again of course!

Edited November 30, 2023 by eightbit

[MMarcoux66]

The seller also offered it to me for $200 + shipping which seems high. What should I counteroffer him for this system that would be fair?

[Boschloo]

12 minutes ago, MMarcoux66 said:

The seller also offered it to me for $200 + shipping which seems high. What should I counteroffer him for this system that would be fair?

In the end, I rejected it because the yellowing was too much to live with. It was FAR too yellow. There will be others.

[MMarcoux66]

22 minutes ago, Boschloo said:

In the end, I rejected it because the yellowing was too much to live with. It was FAR too yellow. There will be others.

Gotcha. I am okay with retrobriting this one if I can get a decent price. Was thinking of countering with $150 but wasn't sure if it was worth it. 

[Boschloo]

1 hour ago, MMarcoux66 said:

Gotcha. I am okay with retrobriting this one if I can get a decent price. Was thinking of countering with $150 but wasn't sure if it was worth it. 

If you do that, he's going to counteroffer with $210. Not a realistic seller.

[MMarcoux66]

Yeah, I think that I will just pass. Realistically, it is not worth a whole lot as it is really to be considered "untested". So, not worth the gamble.