MHP50-B5 Not following Reflow Protocol

[blakebr]

Hello,

On November 27, 2024 I purchased a MHP50-B5 on Order #3392302-0510016134. It arrived a couple days later undamaged.

Since then I have been trying to get it to follow the Reflow Protocol without success. I have been in contact with the MINIWARE user forum in China. They referred me to their download page where version 2.00 of the firmware was available. I updated the firmware to version 2.00 without problems. The Reflow Protocol is still not being followed.

The MHP50 is connected to a 19.5 Volt, 90 Watt power supply through the barrel connector. The default MHP50 programming is set to 90 Watts. See below.

When the MHP50 is told to do the Reflow Protocol its temperature rises from ambient to 140C and then pauses for ~15 seconds. It then rises to 160C and pauses for ~15 seconds. It then rises to 235C for a moment, ~2 seconds, then the temperature starts to drop by what I assume is radiation into the local air because the heating element is turned off. It never gets to any of the program set points. T1 is 220C, T2 is 250C, T3 is 300C.

I placed an unused PCB on the MHP50 to see what happed to the solder. A small portion of the solder melted for 3 to 5 seconds. Any large area of solder did not melt.

The Info panel shows the Volts at 19v, MCU Temp 34C, Resistance 3.9 Ohms, Module BS50-1.

Do you have any ideas what I can try to get it to work? Is there anything I should test?

Bruce

Code: Select all

/********************************************************/
/*             MINIWARE MHP50 Configuration             */
/********************************************************/
T1_Temp   = 220 #(C:100~350 F:212~662)
T2_Temp   = 250 #(C:100~350 F:212~662)
T3_Temp   = 300 #(C:100~350 F:212~662)
Tip1_Temp = 300 #(C:100~400 F:212~752)
Tip2_Temp = 330 #(C:100~400 F:212~752)
Tip3_Temp = 280 #(C:100~400 F:212~752)
HotOvrTim =  20 #(Min:0~999)
SleepTime = 120 #(0:OFF 1~999:Sec)
StdbyTime =  10 #(Min:0~999)
Backlight =   6 #(Brightness:1~9)
TiltAngle =  30 #(20~50)
Volume    =   3 #(0~5)
TempUnit  =   0 #(0:C 1:F)
Turbo     =   0 #(TS80P Power 0:36W 1:60W)
PD_PwrMax =   0 #(0:OFF OR 36~140:36~140W)
DC_PwrMax =  90 #(36~150:36~150W)
Language  =   0 #(0:EN 1:CN 2:DE 3:RU)
RiseTemp  = 150 #(C:100~170 F:212~338)
RiseTime  =  80 #(Sec:60~90)
KeepTemp  = 170 #(C:110~170 F:230~338)
KeepTime  =  80 #(Sec:60~120)
WeldTemp  = 230 #(C:150~260 F:302~500)
WeldTime  =  80 #(Sec:30~180)

[mikeysklar]

The 19v seems off, why would it not register as 20v?

Do you have a larger power supply you can test with? You are probably using the USB-C cable it came with, but have you tested any others?

From the product page:

USB C PD at 20V for 100W, or 20~24V DC for 150W

I've been using the MHP30 with a MacBook AIR M2 30W power supply and USB-C cable that with a monitor. I am at 20v and the MHP30 is melting the solder. 170C I see some off gassing and 205C the solder bubbles and switches liquid. I recall needing to try a few power supply / usb-c cable combinations to get usable full power. This is a new process for me so I'm still getting used to the stencil making, but yesterday was close to usable.

IMG_3136.jpeg (125.78 KiB) Viewed 189 times

IMG_3165.jpeg (359.18 KiB) Viewed 186 times

[blakebr]

Mikey,

The previous tests were a 90 Watt power supply for a laptop. The power was applied through the barrel connector.

I replaced the laptop power supply with a 24 Volt, 10 Amp, 240 Watt power supply. Power was again applied through the barrel connector. No real change.

The configuration file says: - - - - - - - - - Actual:
Rise Temp 150C for 80 Seconds. Looks OK, gets to 140C and 'A' is displayed & 60 pause, beep is heard.
Keep Temp 170C for 80 Seconds. Looks OK, gets to 160C and 'B' is displayed & 60 pause, beep is heard.
Weld Temp 230C for 80 Seconds. Looks bad, gets to 230C, 'C' is not displayed, No pause, beep is heard.

It look like it hits the weld temperature, beeps, shuts down power to the MHP50 hot plate. It does not hold the hot plate at 230C for 80 seconds while the heat moves through the PCB and melts the solder. I put a 0.1 Ohm resistor in series with the 24 volt supply. It shows 20 ma at idol. 5.25 Amps when heating on and off.

The 20 ma after the third beep when the reflow should be holding at 230C for 80 seconds is the problem.

Bruce

[mikeysklar]

Bruce,

This sounds to me like an internal component is compromised.

Have you seen this thread? Some early batches of MHP50 had a fan cord issue causing a low temperature ceiling. It is not a perfect match for your symptoms, but there are other related discussions on in that thread.

[blakebr]

Mikey,

I am more than eager to open up my MHP50 ;-)

However - - - Will this void my 30 day warranty with AdaFruit?!?

Bruce

P.S. Ask my bride of 54 years about taking things apart. Back in 1970 we bought a beautiful 25 inch CRT console color TV. The second day we had it I took the back off and the chassis out and wired in an exhaust fan to extend the tube life. Half way through, my bride came down the stairs, saw parts all over the place, and said "It had better work!" Luckily for me it did.

[mikeysklar]

I can see how an expensive item (converting to todays dollars) such as a 1970 Color TV would be stressful for the family.

Before opening the unit. Are you able to hit 230C with a manual mode? Can it hold it? You don't need to test with a board or stencil. Just checking to see if this strictly related to the reflow protocol or if the unit cannot reach/sustain a high temp at all.

You will be covered under 30-day warranty. This is will be helpful for a better understanding of failure.

[blakebr]

Mikey,

Under Heat I was offered 220C, 250C, 300C. With the 24 Volt 10 Amp power supply it rose rapidly to the selected temperature and over shot by 2 or 3 degrees. It then settled down and held the temperature at the selected temperature until I changed it (10 to 15 seconds). So it looks like the hardware is good.

The MHP50 I received came with Version 1.02 firmware. MINIWARE only has versions 1.00, 1.01, and 2.00 available. The support person said there is no significant difference between 1.01 and 1.02. When the MHP50 cools down I will try pushing 1.01 to see what happens.

Bruce

[mikeysklar]

Thank for doing the temperature check. That does sound like the hardware is functioning correctly leaving the firmware at fault.

FWIW I ask the AI about temperature / timing and I've been manually doing this with my MHP-30. Roughly a min process.

Code: Select all

+-----------+------------------------------------+--------------------+---------------+
| Step      | Description                        | Temperature (°C)   | Duration (sec)|
+-----------+------------------------------------+--------------------+---------------+
| Preheat   | Gently warm the board to reduce    | 100 - 130          | 30 - 60       |
|           | thermal shock and outgas volatiles |                    |               |
+-----------+------------------------------------+--------------------+---------------+
| Soak      | Soak at a moderate temperature to  | ~150               | 60 - 90       |
|           | ensure even heat distribution and  |                    |               |
|           | activate flux                       |                    |               |
+-----------+------------------------------------+--------------------+---------------+
| Reflow    | Increase temp to melt solder paste | 180 - 200 (Pb)     | 30 - 60       |
|           | (Lead-based) or slightly higher    | 210 - 230 (Pb-free)|               |
|           | for lead-free solder               |                    |               |
+-----------+------------------------------------+--------------------+---------------+
| Cool-Down | Remove from heat and allow to      | Ambient            | Until cool    |
|           | cool naturally                     |                    |               |
+-----------+------------------------------------+--------------------+---------------+

[blakebr]

Mikey,

Failure is an option.

Loading MHP50APPV101.hex and watching it change to MHP50APPV101.rdy worked as expected.
When connected to the 24 volt power supply I was presented with a white screen with no text or icons.
No response pushing the buttons.

I loaded MHP50APPV200.hex >>> MHP50APPV200.rdy and the screen is back.

So much for the MINIWARE tech support advice.

Bruce

[mikeysklar]

I wonder if 24v support was in the v1.01 firmware? I did see a mention of 28v coming in later releases.

Regardless, it looks like you have a valid bug with the reflow not holding temperature in the v2.00 firmware. How do you want to proceed?

* Contact miniware to reproduce
* Manually time / set the temp changes
* Return the unit to Adafruit

[blakebr]

Mikey,

I figure I have at least until December 27, 2024 to make this decision (30 days).

I can use manual for a bit to give MINIWARE a chance to fix it (1 week).

If they don't fix the issue I will then ask for a replacement from AdaFruit.
How does return & replace work at AdaFruit?

Bruce

[mikeysklar]

That is fair.

Are you able to use the stock config file for temperature profiles or does that fail at reflow temps as well?

We can authorize a return or replacement in the forums and you e-mail [email protected] with the forum link and your order#.

[blakebr]

Mikey,

It is the stock Reflow temperature profile that fails.

I can set T1, T2, and T3 to the profile temperatures and use Heat.
I must then manually switch through them at the appropriate intervals.

I paid for Reflow to do that for me.

Bruce

[mikeysklar]

Let me know how you would like to proceed. I suspect another unit will exhibit the same behavior as this does look like a firmware problem. If MINIWARE gets back to you saying they can reproduce the issue that would be a great data point.

[blakebr]

Mikey,

The never ending story of the MHP50 firmware...

MINIWARE finally released MHP50UI100.hex. It lets MHP50APP101.hex load and work!

I now can run version 101. It FOLLOWS the Reflow Protocol!!!

So now I gotta work with the MINIWARE folks to get 2.00 fixed.
I will be back to you IF and WHEN they fix it.

I will also try to get them to release version 1.02. The version in the MHP50 AdaFruit sells.

Thank you for working with me on this issue.

Bruce