SF7850 can't reset h4

[axyun]

Had to replace bad fuser lamp. New lamp is good. H4 still flashing. When I try C INT 0 INT display won't go blank. H4 continues to flash right thru simulation , never stopping. Too of control panel and pressed switches directly but still no luck. I would go back with thermostat too but shouldn't machine allow me to get into simulation mode. Is this a oper pwb or main board problem. Possibly one of the print switches for sim (INT ,C or 0)? I could have checked them as I had board out but was so frustrated and wasted so much time, couldn't think straight anymore.Any advice is appreciated . Customer wants to keep this machine and is willing to spend the $ to fix. Already quoted $275 as had to make 2 trips and pay several tolls. Now it will be at least $350. Frank/ActionPhotocopy

[JustManuals]

Re: SF7850 can't reset h4

This Parts & Service manual can now be purchased for $12.77 and downloaded immediately after payment from

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Paul@justmanuals.com

[axyun]

Re: SF7850 can't reset h4

Hi Paul. .I would appreciate it if you wouldn't try to sell a manual to me when I ask for help. After all isn't that what this site is for . I have the service and parts manual. That's how i know the simulation and diagnotic codes. Not all the answers are to be found in the manual. If you have no other response than to sell amanual please refrain from doing so when I request help ont his site. If I want a manual., there is a manual request dept on this site.
I like to wish you a healthy, happy and prosperous new year, Paul. Frank

[lky1978]

Re: SF7850 can't reset h4

Hi Paul. .I would appreciate it if you wouldn't try to sell a manual to me when I ask for help. After all isn't that what this site is for . I have the service and parts manual. That's how i know the simulation and diagnotic codes. Not all the answers are to be found in the manual. If you have no other response than to sell amanual please refrain from doing so when I request help ont his site. If I want a manual., there is a manual request dept on this site.
I like to wish you a healthy, happy and prosperous new year, Paul. Frank

for your case, i think the button switch on panel malfunction. so you need to bring the multimeter to test it.

[axyun]

Re: SF7850 can't reset h4

I have 3 of these print switches(qsw-p0425fczz) in stock though I could have swapped one from another on board that is not critical as mentioned. Is there anything else i should consider? I guess the print switches could be good and I could have a bad circuit in one of the boards. It's just that it is not a local call and want to be as prepared as possible.
It is definate though that a bad thermostat should not stop my accessing the simulation mode, correct? I don't have a thermostat in stock but will check if there is the identical one on one of the machines I have. Frank

[blue_492]

Re: SF7850 can't reset h4

Sounds like sticky buttons on panel.Some time they free up. Start button or c button may be stuck, try pressing them in code order while wobbing moton on each button.

Do to age of machine and your travel, I would try to upgrade machine and take old machine to shop.

[axyun]

Re: SF7850 can't reset h4

Thanks Don. That's good advice. I forgot about sticking buttons. I'll try that before checking print switches with meter. I am keeping another machine in mind thought this guy is limited in $ and does larger size documents and would need the 11x17 feature.Frank

[JustManuals]

Re: SF7850 can't reset h4

Frank, There are other people who read this thread, and they might need the manual.

[blue_492]

Re: SF7850 can't reset h4

Do other people share there manuals at no charge on this site?

[BMSInc95]

Re: SF7850 can't reset h4

LOL that is like repairing an 8-track player. Sorry but it may be time to upgrade to maybe a SF-2020

[moreroof]

Re: SF7850 can't reset h4

try swap the control/operating panel with working one, if it solve the problem then troubleshoot the panel.

[copyguy1989]

Re: SF7850 can't reset h4

I can't remember what the display board looks like but have you tried both CP0P and C00C? I'm thinking it's one of those then 15 and print.
Yes, check those other buttons.

[axyun]

Re: SF7850 can't reset h4

Thanks guys. I was back there today and first made sure no keys were stuck. Then I replace all 3 print switches that are used for simulation (C,Interrupt,0). Still can't get into simulation. The sequence is C,Interrupt,0,Interrupt. It may be a control panel(there are 2, one connected to the other). So it could be either operation panel or possibly main board. Not sure where to go from here. Don't have these old boards anymore. Frank

[Motormount]

Re: SF7850 can't reset h4

The switches on those op panels are wired in a matrix so that a cracked solder connection on one switch can prevent another switch from working. Look for cracked solder, especially on the most used keys, which sometimes can be identified by the wear on the corresponding button itself.
You can also check the schematic to determine where to test for continuity - but not at the key, as your probe will most likely close the circuit.
Finally, timing is everything: if you input the sequence too slowly, it won't work.
Best bet is to upgrade. AR-M207s are plentiful and cheap.

[axyun]

Re: SF7850 can't reset h4

Yhanks Motormount. Frank