laserjet4v lockup

[cameocrew]

Bought me a Laserjet4v from e bay (silly boy??)
Plugged it into my PC and booted. Printer ran up
and display read'05 self test' then 'lang=english'
with that it locked up -not responding to any buttons.
OK I shut printer down checked all leads and other bits and
bobs( toner/doors/paper/pc software driver etc)
Rebooted and same result. shut printer down and
rebooted with 'on line' button pressed -printer
ran up with message 'cold reset' -when button released
'05 self test' then 'lang=english' then lockup.
Shut printer down and searched web for ideas
and found this site. rebooted printer with buttons
'on line/form feed/enter held.
printer ran up with no messages -pressed 'form feed'
and 'enter' -printer briefly displayer 'service'
then '05 self test'/lang=english then lockup
I guess you guys are its last hope before it
receives a 4lb lump hammer message from me
any ideas??
regards Tom.

[Placebo]

Remove any additional memory that has been added as well as any MIO cards, font cards or simm/dimm modules. Basically take out any add-on cards or memory and see if it posts then. If it does then start adding cards back one at a time until it freezes again.

[cameocrew]

Remove any additional memory that has been added as well as any MIO cards, font cards or simm/dimm modules. Basically take out any add-on cards or memory and see if it posts then. If it does then start adding cards back one at a time until it freezes again.
Thanks for that placebo. Removed motherboard? from back no simms or dimms
on board .replaced and booted -same results

[Placebo]

Well if there is no MIO cards installed then it doesn't look good. Maybe try checking/re-seating all the connectors as a last ditch effort if you have no other printers to swap parts with. If all fails it is most likely the motherboard.

[cameocrew]

Well if there is no MIO cards installed then it doesn't look good. Maybe try checking/re-seating all the connectors as a last ditch effort if you have no other printers to swap parts with. If all fails it is most likely the motherboard.
Guess thats it for this printer. Another few hours fiddling with its inners and
outers but with same results 'lang=english' then lockup.
Thanks for advice
Tom.