IR7105 Dark Patches when Test PG

[sunboi]

Hi Guys,

Would appreciate any kind advise from the experts here as i really tried and run out of ideas. Please note that i am not a authorized tech from canon thus please be patience with me. You guys will save me a lot of time trying to figure out whats wrong and I get completely obsessed if it cannot be fixed.

I recently bought the Ir7105 from an exporter for my printing biz. When i did a test print at the supplier's office, everything was okay.

When its back in the office and i have not even change the normal parts which i normally do so and i did a Test PG. It came out. Totally black with the normal grid lines. total black.jpg

I used to have this issue when my laser shutter was damage but when i peek into it, it has red line so i assume its not damage. Next, I change all wires(primary, secondary, Pre-transfer corona) but the problem still persist.

One of my close associates told me that there might be an issue with the potential measuring PCB. But when i checked, the machine did not have one which all of our friends told me its impossible. See attached pic. or is this not where a potential measuring PCB is
Photo 18-11-14 3 15 13 pm.jpg


Anyhow, after scratching head for a long long time, I finally found that i can off the potential measuring in service>copier>option>body>PO-Cnt

After I change this from default 1 to 0. Wohoo, the total black was gone! However!!!!! it came out with this issue.

dark background.jpg
dark patches at the top part from printing & copying!!!

Please! i really run out of idea and i really need to get this machine up!!! Any kind advise would be very much appreciated and I will constantly updates on the changes i did.

[mramlawi]

Hi,

first of all enter the service mode and make a p print ,then make clear dc after that returend the factory values which located on the front door inner.
ps:have u change the primary corona ? Some time it need adjustment cos this issue also try to loose the plastic screw in the primary and let the wire rise up on the grid ur problem will solve .

[sunboi]

Hi,

first of all enter the service mode and make a p print ,then make clear dc after that returend the factory values which located on the front door inner.
ps:have u change the primary corona ? Some time it need adjustment cos this issue also try to loose the plastic screw in the primary and let the wire rise up on the grid ur problem will solve .

Hi meanlawi,

thank you for the prompt reply. May I check where to get the P print. To be frank, after my canon tech friend advise... I had clear the dc con... And enter the value from the inner door. But the problem still persist.

For the adjustment of the corona wire, I will do that first thing in the morning and update in this forum.

any more advise from any kind profs here?

[sunboi]

My concern is right now why did when I did the test print at the supplier's office was perfect but when it got back to my office it's appear the first black printout which I had attached? Could it be something that is experiencing bad connection between the moval?

[sunboi]

Any advise?

[sunboi]

Hi All,

for the benefit of others who come to search for any resolution.

After i change the HVT PCB Board, Everything is back to normal! Cheers

[JPiek]

So the move was probably to bumpy for the PCB ?

[Canuck]

If it returns....

[sunboi]

So the move was probably to bumpy for the PCB ?

Most likely or it might already been faulty. Lesson learn. Change parts by parts in order not to confuse own self =)

[sunboi]

If it returns....

i am not sure if this applies to me as these are used machine from other countries. Till date, i own 5 Ir 7105. Frankly speaking, learnt a lot thru this forum. Anyway, Thanks for the heads up.