Piggyback 4164 to Diagnose Memory Fault

[t0nyt]

Hi

Get the ones that are turned, they have thinner pins. If you have solder paste put some in each before you insert the cable.

Ok thanks

[t0nyt]

Oh well, it turned into a bit of a bodge (for now at least) but it seems to prove the MDV2 spin up at power on is related to the position rather than the MDV

Will leave everything else as it is for now until I have Minerva ROM installed

Many thanks

[t0nyt]

Hi

I get a deja vu, As mentioned Minerva will diagnose any memory fault.
Others will most likely correct me if I'm wrong, but I would start with the logic circuitry for RAM/ROM and the screen could be the cabling to monitor, do you use RGB?

Logic circuitry IC's have arrived, but will wait to fit them until I've checked the memory with Minerva

The least amount of soldering I can get away with the better

Any IC's (logic or RAM) I do replace I'll probably socket

[Chris_68]

Sounds wise! It was just so you had them in case there’s a problem with memory. Update what you get with Minerva installed.

If you decide to desolder then first cut the pins or use a sharp knife. Then desolder pin by pin!!

Good luck!

[t0nyt]

I decided, while I had a free half hour on my hands, to swap what was the untested MDV2 from the broken QL into my working QL to replace the MDV2 that won't format/write

Didn't expect anything, I'm not a lucky person when it comes to this sort of thing, but it works! (for now at least!)

Will eventually fit the old MDV2 into the broken QL, if I get it working, to see what it does in there

[t0nyt]

Sounds wise! It was just so you had them in case there’s a problem with memory. Update what you get with Minerva installed.

If you decide to desolder then first cut the pins or use a sharp knife. Then desolder pin by pin!!

Good luck!

Have fitted Minerva ROM and it now boots (couldn't check RAM total as keyboard not attached currently)

I do get the following on memory check screen though

3BC43BA0
3BC43FA4
00030000

I'll see what I can find in the Minerva manual, but if anyone can advise me in the meantime that would be very welcome please

MDV2 still spins up for a couple of seconds on power on (but not on reset), but will come back to that later

Many thanks

[t0nyt]

I've run ramfail_bas and it reports IC11 as the faulty one

Just got to wait for my memory to arrive now, hopefully tomorrow

[t0nyt]

I've run ramfail_bas and it reports IC11 as the faulty one

Just got to wait for my memory to arrive now, hopefully tomorrow

Well I decided to get ahead of the game and fit a socket in the IC11 position

But I think I've made a right hash of it (I've replaced IC's with sockets on a C64 etc. before so not sure why I messed this one up!)

Will try a memory chip, when they arrive, but I think this QL is going in the breakers box for spares

[Chris_68]

Hi,

What happened when you desoldered IC11?

You will fix it don't worry! Are the logic circuits ok? Did you try several times and got the same result pointing towards IC11?

[t0nyt]

Hi,

What happened when you desoldered IC11?

You will fix it don't worry! Are the logic circuits ok? Did you try several times and got the same result pointing towards IC11?

I think I’ve stripped off a connection on the mobo

I should of taken a picture of the board reverse before I started messing with it to check everything at least looked ok

Minerva booted ok (other than memory error), before my soldering, and several resets always pointed to same IC11 so haven’t touched logic chips

I guess time will tell