QSS-3300 S2 scanner – LED temperature not reaching READY + iris intermittent

[fotoaldoconte@gmail.com]

Ciao a tutti,

Sto lavorando su un Noritsu QSS-3300 con scanner S2 e avrei bisogno di un consiglio tecnico riguardo a due problemi distinti.

Problema 1 – Temperatura LED
Lo scanner non raggiunge lo stato READY.

• La temperatura si mantiene stabile intorno ai ~30–34°C
• Se riscaldo l'unità LED esternamente (utilizzando una pistola termica/un asciugacapelli), la temperatura sale rapidamente sopra i 45 °C.
• Il sistema risponde correttamente e la lettura del termistore appare coerente

Misure effettuate sul connettore P56 (riscaldatori):

• 1a riga: ~60 Ω
• Seconda riga: ~429 Ω
• 3a riga: OL (circuito aperto)

Misure effettuate sulla scheda J390999:

• TP2 ≈ 18,8 V
• TP3 ≈ 16,6 V
• TP4 ≈ 16,4 V

Questo sembra indicare che la scheda di controllo funzioni correttamente e fornisca la tensione corretta, ma il modulo LED presenta due linee di riscaldamento compromesse (una interrotta e una degradata).

---

Problema 2 – Diaframma (apertura)
Durante i test in modalità di servizio:

• I motori dello zoom funzionano correttamente

• Il test del "motore dell'iride" è intermittente:

  • a volte il movimento è udibile
  • a volte non c'è alcun movimento.

• Il sensore dell'iride cambia stato, ma in modo incoerente:

  • non affidabile
  • A volte risponde, a volte no (circa 1 tentativo su 3-4).

• Durante i test, il sensore dell'iride alterna gli stati (BUIO/LUCE), ma non in modo stabile o ripetibile.

L'iride non appare completamente bloccata, ma mostra piuttosto:

• movimento incoerente
• feedback instabile del sensore

---

Qualsiasi suggerimento o esperienza simile sarebbe molto apprezzata.

Grazie!

Edited March 28 by fotoaldoconte@gmail.com

[Dave S]

I only understand posts written in English

[fotoaldoconte@gmail.com]

Salve,
grazie. Ripropongo il problema in inglese.
Sto lavorando su uno scanner Noritsu QSS-3300 con S2 e ho due problemi distinti.
Problema 1: la temperatura del LED non raggiunge lo stato READY
. Lo scanner non raggiunge lo stato READY.
La temperatura del LED rimane intorno ai 30-34 °C.
Se riscaldo l'unità LED esternamente con una pistola ad aria calda/asciugacapelli, la temperatura sale rapidamente sopra i 45 °C.
Il sistema reagisce correttamente, quindi la lettura del termistore sembra coerente.
Misurazioni sul connettore P56 (linee riscaldanti):
Linea 1: circa 60 Ω
Linea 2: circa 429 Ω
Linea 3: OL / circuito aperto
Misurazioni sulla scheda J390999:
TP2 ≈ 18,8 V
TP3 ≈ 16,6 V
TP4 ≈ 16,4 V
Da queste misurazioni, sembra che la scheda di controllo stia fornendo tensione correttamente, ma il modulo LED potrebbe avere linee riscaldanti danneggiate: una aperta e una degradata.
Problema 2 – Iride / diaframma intermittente Durante i test in modalità di servizio:
i motori dello zoom funzionano correttamente.
Il test del motore dell'iride è intermittente:
a volte sento il movimento,
a volte non c'è alcun movimento.
Il sensore dell'iride cambia stato, ma in modo incoerente:
non affidabile,
a volte risponde, a volte no (circa 1 volta su 3-4).
Durante i test, il sensore dell'iride alterna tra CHIARO / SCURO, ma non in modo stabile o ripetibile.
Il diaframma non sembra completamente bloccato, ma presenta
movimenti irregolari e
un feedback instabile del sensore.
Le mie domande sono:
in base a questi valori di resistenza del riscaldatore, riterreste difettoso il gruppo riscaldatore LED?
Il problema del diaframma potrebbe essere causato più probabilmente dal motore del diaframma, dal sensore o da un bloccaggio meccanico del gruppo diaframma?
Esiste qualche punto debole noto nell'unità ottica dello scanner S2 correlato a questi sintomi?
Ogni consiglio è ben accetto. Grazie.

English version:

Hello everyone,

I’m working on a Noritsu QSS-3300 with S2 scanner and I would like some technical advice regarding two separate issues.

Problem 1 – LED Temperature
The scanner does not reach READY status.

• Temperature remains stable around ~30–34°C
• If I heat the LED unit externally with hot air (hair dryer), the temperature quickly rises above 45°C
• The system responds correctly and the thermistor reading appears consistent

Measurements taken on connector P56 (heater lines):

• 1st line: ~60 Ω
• 2nd line: ~429 Ω
• 3rd line: OL (open circuit)

Measurements on the J390999 board:

• TP2 ≈ 18.8 V
• TP3 ≈ 16.6 V
• TP4 ≈ 16.4 V

This seems to indicate that the driver board is working and supplying correct voltage, but the LED module has two compromised heater lines (one open and one degraded).

Problem 2 – Iris (aperture)
During service mode tests:

• Zoom motors are working correctly

• The “Iris motor” test is intermittent:

  • sometimes movement is audible
  • sometimes there is no movement at all

• The iris sensor changes state, but inconsistently:

  • not reliable
  • sometimes responds, sometimes not (about 1 out of 3–4 attempts)

• During testing, the iris sensor alternates between DARK/LIGHT, but not in a stable or repeatable way

The iris does not appear completely stuck, but rather shows:

• inconsistent movement
• unstable sensor feedback

Any suggestions or similar experiences would be greatly appreciated.

Thank you!

Edited March 30 by fotoaldoconte@gmail.com

[kodak_service]

Hi, Aldo,

There are two problems here:
1. One of the heaters in the LED unit is broken.
2. The flexible flat cable that controls the diaphragm is broken.
Unfortunately, you can't fix this yourself. Only a qualified service engineer can do it in their workshop.

 

[fotoaldoconte@gmail.com]

Hello,

Thank you for your reply.

So, if I understood correctly, there are two faults:

1. one heater in the LED unit is damaged
2. the flexible flat cable for the iris is damaged

Could you please tell me:

• the approximate repair cost
• what parts would be replaced
• what repair procedure you would perform
• whether I need to send the complete scanner or only specific parts

Also, in my Kodak DLS setup, it seems I cannot continue working properly, even for digital jobs only, if the scanner is not installed or not detected.

Is there any temporary solution or workaround to use the machine for digital work only while the scanner is under repair?

Thank you.

 

[fotoaldoconte@gmail.com]

On 29/03/2026 at 10:39, Dave S said:

Capisco solo i post scritti in inglese

Hello everyone,

I’m working on a Noritsu QSS-3300 with S2 scanner and I would like some technical advice regarding two separate issues.

Problem 1 – LED Temperature
The scanner does not reach READY status.

• The temperature remains stable at around 30–34°C
• If I heat the LED unit externally using hot air (for example, a hair dryer), the temperature quickly rises above 45°C
• The system responds correctly, and the thermistor reading appears consistent

This seems to suggest that the temperature sensing circuit is working, but under normal conditions the LED unit does not heat up enough by itself to reach the required READY threshold.

I also took some measurements on the connector / power supply side to check whether the LED unit is being driven correctly.

Problem 2 – Intermittent iris diaphragm movement
There is also a second issue involving the iris diaphragm, which moves intermittently or behaves abnormally.

I’m trying to understand whether these two problems could be related, or if they should be considered completely separate faults.

Has anyone experienced a similar issue on the S2 scanner, especially regarding:

• LED unit not reaching operating temperature
• possible weak LED drive / power supply problem
• thermistor circuit behaving correctly but insufficient self-heating
• intermittent iris mechanism or iris motor issues

Any technical suggestions, known failure points, or checks to perform would be greatly appreciated.

Thank you in advance.

[kodak_service]

Aldo,

1. The entire scanner is needed for repairs.
2. The cost is best discussed with the engineer willing to do the work. I can't do this, as shipping the scanner to Russia and back to Italy is currently a very complex and expensive task.
3. For the minilab to work without the scanner, the QSS-3300PRO software must be installed, but it has a different interface and is in English.
4. I can send instructions for modifying the scanner circuit to restore heating using a bypass circuit, but I cannot guarantee that this will work correctly.

Igor

[fotoaldoconte@gmail.com]

Hello,

At the moment, the scanner is still working, and I hope it will not fail suddenly, because that would be the main problem.

I am mostly concerned about the future.

Unfortunately, film processing is not in high demand here. I only get a few films per month from time to time. If I find a good opportunity at a reasonable cost, I could be interested, but I would not like to spend more than what I can realistically earn from film business.

Thank you very much for your cooperation.

Best regards.

[Dave S]

Both of these are common problems on the S2 scanner.
The temperature problem is due to the internal heaters inside the light source failing.
It is possible to fit an external heater to help with the issue.

I wouldn't worry too much about the iris motor error, many S2 scanners have had this problem for many years, it generally doesn't seem to get any worse, normally after 2-3 error clears it works normally again.
It is a big job to repair it, and realign the lens again.

[fotoaldoconte@gmail.com]

Hello,

Thank you very much for your reply and for sharing your experience.

It is very useful for me to know that both of these problems are common on the S2 scanner.

Your explanation about the temperature issue confirms what I was suspecting, that the problem is related to the internal heaters of the light source. The idea of using an external heater is also very interesting.

I also appreciate your comment about the iris motor error. It is reassuring to know that many S2 scanners continue to work for years with this issue and that it does not always get worse quickly.

I understand that repairing it properly, and especially realigning the lens, is a complex job.

Thank you again for your technical advice and for taking the time to answer me.

Best regards,
Aldo

[Minilab service]

Take powerful aluminum wire wound resistor and mount it on light source. Under resistor use thermal paste. Connect resistor to standard heater control circuit. Then this resistor can heat light source ( from outside ) and light source can reach working temperature.

LED unit has three heaters. When heaters are ON from control circuit supplied 36V . Two heaters are on B-G LED and one on R-IR LED . Resistor can connect to all three heater control circuits using three powerfull ultra low drop schottky barrier diodes.