Trouble Code "H4-04" on Sharp DX-C311

**draph** · 01-07-2011

An issue I've seen many times over the years here in cold old Minnesota. Does the code tend to pop up first thing in the morning? Does the customer turn the heat down over night? Machine needs to start warm up from an ambient room temp. of 70 degrees. If it's starting from 60, odds are you will get the code.

**RascalMJ** · 01-08-2011

Originally Posted by CBMWilson

If i have to change the temps, I'll generally change 43-1 A-I down by 5 degrees. Any more and I start worrying about tracking or poor fusing.

That particular code appears to refer to the TH_EX which is the external heat roller thermistor. It requires a higher temperature setting than the upper or lower heat rollers. You might also try to increase the time allowed to come to ready which appears to be 83 seconds (item L on 43-1).

Is there any thing external that could affect warm-up? Nearby ventilation, exterior window?

I'm working from the MX-C311 manual so hopefully the settings are the same for the DX version.

Yeah, I tracked down the pre-heat temp (I just put 43.1, but I think it was "Z", from memory).

AWESOME TIP on the time to pre-heat, I would be more comfortable trying that....

Originally Posted by draph

An issue I've seen many times over the years here in cold old Minnesota. Does the code tend to pop up first thing in the morning? Does the customer turn the heat down over night? Machine needs to start warm up from an ambient room temp. of 70 degrees. If it's starting from 60, odds are you will get the code.

Yeah, we were kind of trying to determine that when the customer started getting frustrated, so we swapped the machine to see if it happened with 2 different machines. The one in question is now in our office and I am testing the morning thing, and so far, we also haven't heard back from the customer either. Kinda weird, but I will take it

**RascalMJ** · 02-07-2011

Originally Posted by RascalMJ

Yeah, I tracked down the pre-heat temp (I just put 43.1, but I think it was "Z", from memory).

AWESOME TIP on the time to pre-heat, I would be more comfortable trying that....

Yeah, we were kind of trying to determine that when the customer started getting frustrated, so we swapped the machine to see if it happened with 2 different machines. The one in question is now in our office and I am testing the morning thing, and so far, we also haven't heard back from the customer either. Kinda weird, but I will take it

Well, we brought back the machine about 4 weeks ago and haven't had a problem with it UNTIL today.

As mentioned earlier I bumped up the warm up time with sim 43-1, increased it from 83 to 120. I was hoping this had taken care of the issue, but it threw the code this morning at about 11am after it was in standby mode.

I will continue to monitor it. A month without the code is better than every other day.... but I would like to see it go away forever.

**RascalMJ** · 11-09-2011

...now that it is getting colder, this rascally little code is popping back up.

I tinkered with 43-1 "AN" a little in the hopes that it would curb the code, but no luck. (70 to 119)

Any thoughts on what to try next?

**Akitu** · 11-09-2011

I've been looking over this thread just seeing what's been suggested... An extra perspective never hurts. Whether or not a suggestion is correct, I find that the more suggestions I have, the more likely I am to bounce around between ideas and find a good angle to look at the problem.

I did notice that the other factors that might cause an H4-04 haven't been mentioned. You've already confirmed that it's solely the fuser not warming up in time, and not the PCU PWB?

Fuser warm up times have already been adjusted, and you've mentioned that it was a fuser that worked perfectly fine in the shop, however, does the lamp actually function correctly? I've had 1 instance where I did just that, and somehow the heat lamp wound up breaking in transport, even though I did everything I should and even had the proper packaging. Mystery breaks always kick you in the rear!

The best I can come up with early in the morning, perhaps as my brain thaws out I'll have better answers throughout the day.

**RascalMJ** · 11-09-2011

Originally Posted by Akitu

I've been looking over this thread just seeing what's been suggested... An extra perspective never hurts. Whether or not a suggestion is correct, I find that the more suggestions I have, the more likely I am to bounce around between ideas and find a good angle to look at the problem.

I did notice that the other factors that might cause an H4-04 haven't been mentioned. You've already confirmed that it's solely the fuser not warming up in time, and not the PCU PWB?

Fuser warm up times have already been adjusted, and you've mentioned that it was a fuser that worked perfectly fine in the shop, however, does the lamp actually function correctly? I've had 1 instance where I did just that, and somehow the heat lamp wound up breaking in transport, even though I did everything I should and even had the proper packaging. Mystery breaks always kick you in the rear!

The best I can come up with early in the morning, perhaps as my brain thaws out I'll have better answers throughout the day.

Well, I guess that could be the case..... this whole time (months) we have had it in the shop and have been using it as our sole machine. We don't do high volume, but we do enough to put it through the wringer a bit. NO ISSUES at all until this morning (slightly chilly in Ohio, but not bad).

The issue I have is that we are kind of small potatoes and I highly doubt my boss will go for ordering a PCU PWB to test this theory (above) and I don't really have a machine to pull one off of to try and test that have. Add to that that the machine does seem to go months at a time without the error....... it would make this type of troubleshooting all the more difficult. It does make sense though (to be the PCU PWB) as we have put several fusers in this machine and both have the issue (which is what lead me to settings or board, in the first place.

There are SO many fuser warm-up (related) settings, I am not sure which ones for sure I should be using and their effectiveness for this code. I guess I will keep plugging away, and see what happens.

**Akitu** · 11-09-2011

Originally Posted by RascalMJ

Well, I guess that could be the case..... this whole time (months) we have had it in the shop and have been using it as our sole machine. We don't do high volume, but we do enough to put it through the wringer a bit. NO ISSUES at all until this morning (slightly chilly in Ohio, but not bad).

The issue I have is that we are kind of small potatoes and I highly doubt my boss will go for ordering a PCU PWB to test this theory (above) and I don't really have a machine to pull one off of to try and test that have. Add to that that the machine does seem to go months at a time without the error....... it would make this type of troubleshooting all the more difficult. It does make sense though (to be the PCU PWB) as we have put several fusers in this machine and both have the issue (which is what lead me to settings or board, in the first place.

There are SO many fuser warm-up (related) settings, I am not sure which ones for sure I should be using and their effectiveness for this code. I guess I will keep plugging away, and see what happens.

If you're adjusting the warm up times and still getting the code, leads me to believe it's either a bad board or something wrong with the internals of the fuser.

Another note worth mentioning, is it the old MXC/DXC-311 fuser, the C31FU or the upgraded C32FU? Not that it's entirely relevant. Do a lamp test on it and see if it's heating up properly.

Brain's still thawing out apparently. Haha

**RascalMJ** · 11-09-2011

Originally Posted by Akitu

If you're adjusting the warm up times and still getting the code, leads me to believe it's either a bad board or something wrong with the internals of the fuser.

Another note worth mentioning, is it the old MXC/DXC-311 fuser, the C31FU or the upgraded C32FU? Not that it's entirely relevant. Do a lamp test on it and see if it's heating up properly.

Brain's still thawing out apparently. Haha

I am still relatively "new" to all this. I have never done a lamp test, but I will look into it. My only thoughts on it though is that the machine functions well 98% of the time. It seems to only get the code early in the morning and when the temperature dips a little outside. I would think that I would see much more issues on a day to day level if it where in fact a board or actual fuser issue.

Thanks for responding and giving ideas...... it does help to get the brain going and bounce ideas around

**Akitu** · 11-10-2011

Originally Posted by RascalMJ

I am still relatively "new" to all this. I have never done a lamp test, but I will look into it. My only thoughts on it though is that the machine functions well 98% of the time. It seems to only get the code early in the morning and when the temperature dips a little outside. I would think that I would see much more issues on a day to day level if it where in fact a board or actual fuser issue.

Thanks for responding and giving ideas...... it does help to get the brain going and bounce ideas around

Sim 5-2 will get you your lamp test. If what you say about the temperature dip is true, then I'd have to assume the only reasonable solution is for the customer to keep the temperature in the office regulated a bit more, or wait a little later in the day to start it up. Perhaps adjusting the warm up time is still the solution as well, I can't say for sure as I've not had such a problem with an H4 code as you're having. Best case scenario it's a faulty thermistor and you can replace it for pennies.

**RascalMJ** · 10-21-2013

Well, funny story.

I ended up needing to use the PCU and MFP PWB from this machine (our office machine) to troubleshoot a problem at a customer site (a crazy problem that I ended up hi-jacking this thread on).

Anyway, now this silly H4-04 code is coming back, but now it's at the customer. UGH

So, it seems likely that is was either the PCU or MFP PWB all along. Fun stuff.