Ricoh 1232c intermittant print quality fault

[tcs04]

That looks like a blocked transfer cleaning unit on top of the PCU, which matches your description of the waste toner being full(!) Easily removed, dismantled and cleaned. When you have it on the bench check the cleaning auger turns freely. Could be the transfer unit lift clutch, has the same effect and will normally make it hard to remove the pcu due to the lift cam being in the wrong position.

You can get some idea that the problem in this area as follows.

Perform a "Clean adjust" via user tools then take 3 A3 white copies in full colour mode, You will often (But not always) see the I.D patches on the 1st copy.

[jonbonse]

teebee1234 and tcs04

I returned to try what you had suggested. . . .

I replaced the drive assy with one from a used machine but the fault remained. . . . . . I also swapped the other drive unti (black casing one) to see but no luck. . . . .

I have already cleaned the transfer belt unit to remove the blockage in the chute. . . . .

Think its time I called it a day on these models!