HP C8180 All-in-One Printer schematic

[Brunner8]

Hi!
It's been a while since I perused this Forum and I am in need of its services again.
I hope someone can help me.

I have the HP C8180 all-in-one printer (scanner, copier, printer) (no Fax)... and it has developed trouble.  I have found out what I need to do to fix it.

But in trying to do so, I'm afraid I damaged one of surface mount resistors on the circuit board.  I need a schematic of the printer (and/or circuit board) in order to know what resistor value it was that I damaged.

I did some initial internet searching and found no schematic for this printer.  I have not tried to contact HP as the printer is long out of warranty.  And I have read other peoples comments that HP cannot be contacted in any case.  I would not know how to contact them.  Maybe someone reading this knows how to contact them and can tell me who at HP can actually give me some results to my questions rather than a runaround.  I have tried their website and all I get is the runaround self help which seems to go in circles and doesn't come anywhere near to addressing my problem.

But what I feel like I need to start to fix this new problem I have created is a schematic of the printer) or more precisely, the value of the resistor I damaged). It is one of the surface mount types with no numbers on it.  Exceedingly tiny, it is.  It is on the part of the circuit board labeled R 12 13.

Can anyone give me some leads?

Thanks and I await any replies.  Please bear with me if I don't respond quickly.  My work schedule permits me little free time.

Thank you.

[DaveLembke]

In this situation, HP would very rarely release schematics for fear that someone would use their designs illegally. Even on obsolete products the manufacturers will retain the schematics as ownership of such and they are not required to provide them to customers.

If your really lucky and know the resistor location such as R241, you can request for HP to share with you the value of this single resistor and maybe they will help you. However the last time I had to deal with HP Support I was talking with a guy in India who was following a flow chart for customer service and I couldnt get him to answer anything on his own. I even informed him that I am not a regular user of HP products, but I field service them and while performing this maintenance on a business line laser printer a tab snapped to a manual feed door, and so I need this plastic door piece that had a part number like 35-098638 on the mold of the plastic part, and can you connect me to someone who can sell me this plastic part. I was met with no assistance from HP. I ended up finding a guy on ebay selling a DOA unit, and I worked out a deal to buy this door of this dead printer for $20 which included shipping, and $75 to fix this problem wasnt worth it to then also have to pay to dispose of the carcass. He was selling the DOA printer for $25 with $50 shipping. I guess this was the last time he decided to post it for sale, I was the only bite he had of interest on it, and he agreed to make something on it vs throw it away as a total loss.

If you know that its this specific resistor, I'd try to find a same model printer that is mechanically dead but powers up on ebay and buy it to use for parts for this printer if its worth doing so. With these printers so inexpensive, its usually a better choice to replace the printer. However maybe you can also work out a deal to buy just this board from the seller and have the seller keep the carcass like I did for like $20.

[Brunner8]

Hi and thanks for the reply.  I apologize for my tardiness in finding sufficient time to interact with you all.

Before I tackled the repair of this resistor, I decided to look over the Internet one more time for a lead.  It bothered me that some SMD resistors on the circuit board were labeled and some were not.  This must mean something, I thought.

So I stumbled across a site that mentioned that unlabelled (or sometimes just black in color) resistors are nothing more than zero ohm resistors that are used where a jumper wire is needed on a board.  By letting the automation machine install these zero ohm resistors on a board while they install all the other components, it saves money by letting the machine do the work rather than having a person physically install jumper wires where needed.

So I looked over my circuit board and it looked like there may be several unlabeled resistors in the vicinity of integrated circuits as well as elsewhere on the board and I suddenly recalled my electronics classes of 30 years ago when we would breadboard circuits and would tie together pins of the IC chip on the breadboard with a jumper wire.  Suddenly it made a little sense to me.  My damaged resistor may be nothing more than a zero ohm resistor.

So I decide to take a chance and solder bridged together the two holes where that resistor had been and decided to try the printer.  What did I have to lose?  I'd just have to buy a new printer anyway.

So far, it has worked just fine for over a week now.  I feel like I have finally solved my problem and learned a little something about zero ohm SMD resistors along the way.

I had considered your idea of finding the same kind of my printer on ebay and buying it for parts.  I may have to do that someday if I keep on wanting to fix mine rather than buying a new one.  But it was a relatively easy fix once I knew what to do and I feel like I've saved $300 if I were to have had to replace it with a similar one.

Thanks and I would consider this problem solved.  Knock on wood!!